Chaotic dynamics techniques have been utilized in encryption. Such chaotic dynamics techniques have some features such as sensitive dependence on initial conditions, ergodicity, and/or cycle tending to infinity. Such chaotic dynamics techniques may be utilized to generate pseudo-random numbers under the control of certain parameters. Therefore, chaotic cryptography has aroused extensive attention, and many scholars have proposed their chaotic cryptosystems in recent years. However, some chaotic cryptosystems based on these chaotic dynamics techniques may have relatively lengthy encryption times and/or may produce resultant ciphertext that may be several times longer as compared to an initial plaintext file.